Effect of chronic immune system activation on the rate, efficiency, and composition of growth and lysine needs of pigs fed from 6 to 27 kg.

Abstract

The influence of a low and a high level chronic immune system (IS) activation on growth and dietary nutrient needs of pigs was evaluated. All pigs were of a single genetic strain and geographical site of origin, and the low and high IS pigs were created by physically isolating pigs from or continuously exposing pigs to major vectors of environmental antigen transmission. In each IS group, four littermate barrows in each of six litters were allotted at 25 +/- 2 d of age to one of four dietary amino acid regimens (.60, .90, 1.20, or 1.50% dietary lysine. Dietary lysine concentrations were achieved by altering the ratio of corn to soybean meal resulting in lysine being the first-limiting amino acid in each diet. Pigs were individually penned in facilities maintained at 25.6 +/- 2 degrees C and allowed to freely consume feed from 6.2 to 26.5 kg BW. On the basis of the differences in serological antibody titers, lymphocyte CD4+:CD8+ ratios, and serum alpha-1-acylglycoprotein concentrations, low and high levels of IS activation were established and maintained during the study. Minimizing the degree of chronic IS activation resulted in greater feed intakes (P < .09), body weight and protein gains (P < .01), gain:feed ratios (P < .01), and body leanness (protein:lipid, P < .01). The level of IS activation did not influence the partial efficiency of energy utilization for body protein and lipid accretion. To allow their greater capacity for body growth and protein accretion to be expressed, the low IS pigs required greater dietary lysine concentrations and daily lysine intakes than high IS pigs.

Board Invited Review: Management and feeding strategies to ameliorate the impact of removing antibiotic growth promoters from diets fed to weanling pigs

“…This hypothesis is consistent with the fact that a stimulation of the immune system will reduce pig performance (Williams et al 1997).…”

Desempenho e excreção de nitrogênio de leitões dos 9 aos 25 kg alimentados com dietas com diferentes níveis de lisina digestível e proteína bruta

“…O ganho de peso médio diário sofreu efeito quadrático (P<0,01) dos níveis de lisina digestível verdadeira e apresentou o melhor Tabela 1 -Composições percentual e química das rações experimentais Neto et al (2000), estudando níveis de lisina total entre 1,3 e 1,7% em rações com 21% de PB, observaram resposta linear crescente do ganho de peso médio diário aos níveis de lisina para leitões de ambos os sexos na fase dos 5 aos 15 k g. De acordo com Williams et al (1997), essa diferença nos resultados de alguns trabalhos pode estar relacionada à linhagem utilizada, ao ambiente e ao padrão sanitário, uma vez que a ativação permanente ou temporária do sistema imunológico dos leitões também pode afetar as exigências de aminoácidos.…”

Digestible lysine for barrows of genetic lines selected for meat deposition from 60 to 100 days of age

“…According to Sthaly et al (1994), the response of ADG to dietary lysine level depends on the animal genotype and growth potential. Yen et al (1986) affirms that performance and carcass meat deposition responses may be associated with the level of dietary lysine demand due to a higher demand of this amino acid for protein deposition and its high concentration in the muscle tissue of pigs.…”

“…The amino acid demands of pigs can be affected by different factors such as ambient temperature and immune challenge levels (Williams et al, 1997;Braumann et al, 2002;LeFloc'h et al, 2004;Trevisi et al, 2009). Besides these factors, the inconsistency in the daily weight gain response resulting from the lysine levels observed among the studies may be related to differences in the genetic potential for lean gain of pigs.…”